1. Field of the Invention
The present invention relates to a thin film transistor (TFT) array substrate and a fabricating method thereof, in particular, to a TFT array substrate operable with a high conducting current and a fabricating method thereof.
2. Description of Related Art
TFTs have been widely employed for controlling circuit signals. They are also employed in the art of flat displays to control the inputting/outputting operation of signals, and facilitating with storage capacitors to upgrade passive driving to active driving, thus improving displaying quality thereof.
In designing pixel electrodes, when considering how to efficiently utilize characteristics of elements, signals are also to be avoided from coupling to each other. Specifically, displays used for viewing active programs having higher refreshing frequencies require not only used elements having better discharging features, but also signals being designed not to likely coupled to each other, so that better displaying quality can be obtained.
FIG. 1 is a schematic diagram illustrating a capacitor circuit of a conventional TFT liquid crystal display (LCD). FIG. 2 illustrates voltage waveforms of the conventional TFT LCD of FIG. 1.
Referring to FIGS. 1 and 2, voltage variation of the TFT, (mainly the variation of the voltage 10 of a scan line) often causes a feed through voltage via a parasitical capacitor (mainly a gate/drain parasitical capacitor Cgd), and therefore causes a display electrode voltage 20 downwardly deviated a value of ΔV. In an ideal consideration, a common voltage 30 is downwardly adjusted ΔV to another common voltage 40 to compensate the voltage difference caused by the feed through voltage, or a storage capacitance Cs is to be increased to the correct the ΔV caused by coupling to each other of the signals.
However, unfortunately, increasing the storage capacitor exhibits its advantage only if the discharging feature of the TFTs is also improved. Otherwise, it will be hard to charge the storage capacitor up to a desired level in a certain time, so that gray levels thereof won't be displayed correctly.